reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://git.kernel.org/pub/scm/linux/kernel/git/martin.lau/bpf-next.git/commit/?id=0c332d2a7030235b72caf88dc472503632c542d6
        git remote add martin-lau-bpf-next https://git.kernel.org/pub/scm/linux/kernel/git/martin.lau/bpf-next.git
        git fetch --no-tags martin-lau-bpf-next skb.tstamp_type
        git checkout 0c332d2a7030235b72caf88dc472503632c542d6
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=openrisc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=openrisc SHELL=/bin/bash net/core/